This invention relates generally to methods and apparatuses for authenticating a sample product, and more specifically, to methods and apparatuses for providing light-emissive compounds for use with product authentication equipment.
Authenticating and monitoring products to discriminate between very similar complex mixtures is useful for various reasons. For example, the use of counterfeit substances (e.g., misbranded product from a competitor or misformulated product from a licensee/franchisee) should be detected to preserve the integrity of a brand. Also, low quality substances (e.g., diluted or misformulated product) should be quickly and conveniently detected for appropriate correction.
One particular industry that could benefit from such authenticity testing and monitoring is the beverage industry. With respect to monitoring production of the beverage, a simple, quick and product specific at-line test to determine whether the beverages being produced are within specification is desirable. Typically, the beverages are being bottled at a rate of 2000 bottles/minute. Therefore, standard off-line analytical techniques for monitoring product quality, such as GC/MS or HPLC, are complex and time consuming in that the beverages that are being tested have already been introduced to the market. A desirable monitoring procedure should provide relatively instant response time, be usable by non-scientific personnel, be accurate (e.g., having an error rate of less that 2.5%) and survive harsh plant environments.
With respect to product authentication, an example of an industry that could benefit is the beer industry. For example, at-line testing allows a determination as to whether a particular tap at a pub was actually serving authentic beer, without being sensitive to batch-to-batch variability of the a particular brand. Similarly, detection of dilution of a product may be important to the distilled spirits industry.
Commonly assigned U.S. Pat. No. 5,753,511, which is herein incorporated by reference in its entirety, discloses an automated method of developing a database to store information for xe2x80x9cfingerprintxe2x80x9d-type analysis of products (even as to product lot numbers and batch). The automated analysis is a method of evaluating and discriminating products, even within a narrow field or industry, competing and otherwise, to establish authenticity or point of origin of the product. The invention therein relates to an automated method for identifying key ingredients and/or the relative amounts of key ingredients in products mixed with light-emissive compounds. Scanning for light emission of a predetermined wavelength when the sample product is mixed with the light-emissive compound is used when comparing the sample product to a fingerprint.
The laboratory equipment used to authenticate the sample referred to in ""511 is not easily and cost effectively transported. Thus, determining product authenticity on site, either at manufacturing points, at distribution points, or at consumption points is impractical.
Co-pending U.S. patent application Ser. No. 09/232,324, assigned to the present assignee and herein incorporated by reference in its entirety, discloses a portable product authentication device and a method of authenticating products. One embodiment disclosed therein requires a proper mixing of both the light-emissive compound and sample product prior to testing the sample for product authenticity. Although effective, mixing of the sample product and the light-emissive compound on-site can be cumbersome and time-consuming and may require a certain skill level.
In another embodiment disclosed in application ""324, the light-emissive compound may be formed on a chip and the chip, together with a small amount of sample, is placed in the authentication device to determine the authenticity of the product. As discussed therein, the light-emissive compound may be attached to the chips through any physical or chemical means including covalent and non-covalent bonding. For example, the light-emissive may be dissolved in a solvent, then applied at a preselected concentration to the surface of the chip.
The solvent is then evaporated away, leaving the light-emissive compound non-covalently attached to the surface of the chip. Although this results in a simple solution to providing light-emissive compounds without requiring mixing, the resulting chip may be costly and susceptible to damage.
To overcome this particular disadvantage, also disclosed in ""324, the light-emissive compound may be covalently attached to the surface of the chip. In this instance, the light-emissive compound may have groups reactive under appropriate conditions with groups on the surface of the chip, which may be reactive groups of the chip per se, or may be linker molecules attached to the surface of the chip. Such cross-linking, however, often requires a labor intensive process, resulting in a costly product. In addition, the cross-linking molecules may interfere with a proper reading of the light emission. For example, current microarray technology teaches the art of immobilizing chemistry for the detection of DNA specific or protein specific sequences. The amino-silane surface chemistry allows a fixed molecule to bind products for applied genomic gene expression studies and medical diagnostic information. The inventors of the present invention have found that adopting such technology for use in binding light-emissive compounds met with limited success.
Another example of providing light-emissive compounds is disclosed in co-pending U.S. patent application Ser. No. 09/173,814, assigned to the present assignee and herein incorporated by reference in its entirety, wherein a microplate may be used in place of the above-mentioned chip. As disclosed therein, the microplate includes a plurality of wells formed in the surface of the microplate. Light-emissive compounds are placed in the wells and attached thereto by directly bonding to the surface or through the use of a linker molecule or incorporated into the matrix created by the base material of the microplate itself. In addition, the invention therein describes the use of a dried light-emissive compound on the microplate or the microplate is packaged.
What is therefore needed is a simple, low cost method and apparatus that provides light-emissive compounds for reaction with a sample product in an environment that is or simulates a liquid solution and that provides the ability for authenticity testing and monitoring of sample product at-line.
The present invention features a method and apparatus for on-site verification of product authentication and quality. A microplate having a substrate includes a light-emissive compound thereon. The substrate provides immobilization of the light-emissive compounds and provides a three-dimensional environment similar to free solution for reactions with the product sample to occur. The microplate may include any material having desired light reflective properties and a surface to retain the light-emissive compounds therein. A metered amount of light-emissive compound is placed on the microplate by any desired metering method, such as hand-metering by skilled technicians, automatic metering using robotic equipment, or printing using for example, piezoelectric dispensing technology. Once the light-emissive compound is applied to the substrate, the microplate may be sent to the test site where product testing is to be performed. A sample product is placed on the microplate and the light-emissive compound thereon is free to react with key ingredients in the sample product. Light emission from the light-emissive compound and the key ingredient is compared to a fingerprint.
In one illustrative embodiment of the invention, a microplate is provided. The microplate includes a solid base and a porous substrate layered on the base. At least one light-emissive compound is absorbed in the substrate in a manner to allow a sample placed on the microplate to react with the at least one light-emissive compound.
In another illustrative embodiment of the invention, a microplate is provided. The microplate includes a solid base having a top wall. At least one well is integral with and opens into the top wall. The at least one well defines an inner surface. At least one light-emissive compound is deposited into the at least one well to allow a sample placed on the microplate to react with the at least one light-emissive compound in the well. A semi-permeable membrane is formed over the at least one well. The semi-permeable membrane is adapted to allow the sample to permeate from outside the at least one well into the at least one well while retaining the at least one light-emissive compound within the at least one well.
In yet another illustrative embodiment of the invention, a microplate is provided. The microplate includes a solid base and at least one light-emissive compound held to the base to allow a sample placed on the microplate to react with the at least one light-emissive compound. A barrier is formed on the base and is adapted to transfer a desired portion of the sample to the at least one light-emissive compound while holding the at least one light-emissive compound to the base.
In still another illustrative embodiment of the invention, a system for verifying authenticity of a sample product is provided. The system includes a microplate and a product authentication device for reading the microplate. The microplate includes a solid base and a porous substrate layered on the base. At least one light-emissive compound is absorbed in the substrate to allow a sample placed on the microplate to react with the at least one light-emissive compound. The authentication device includes a light source for irradiating the microplate with a predetermined wavelength of light, an optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic, and a controller coupled to the optical detector for receiving the sample characteristic and comparing the sample characteristic to a fingerprint.
In another illustrative embodiment of the invention, a system for verifying authenticity of a sample product is provided. The system includes a microplate and a product authentication device for reading the microplate. The microplate includes a solid base and a top wall and at least one well integral with and opening into the top wall. The at least one well defines an inner surface. At least one light-emissive compound is deposited into the at least one well to allow a sample placed on the microplate to react with the at least one light-emissive compound in the well. A semi-permeable membrane is formed over the at least one well. The semi-permeable membrane is adapted to allow the sample placed on the microplate to permeate from outside the at least one well into the at least one well while retaining the at least one light-emissive compound within the at least one well. The authentication device includes a light source for irradiating the microplate with a predetermined wavelength of light, an optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic, and a controller coupled to the optical detector for receiving the sample characteristic and comparing the sample characteristic to a fingerprint.
In yet another illustrative embodiment of the invention, a system for verifying authenticity of a sample product is provided. The system includes a microplate and a product authentication device for reading the microplate. The microplate includes a solid base and at least one light-emissive compound held to the base. A barrier is formed on the base and is adapted to transfer a desired portion of sample placed on the microplate to the at least one light-emissive compound while holding the at least one light-emissive compound to the base. The authentication device includes a light source for irradiating the microplate with a predetermined wavelength of light, an optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic, and a controller coupled to the optical detector for receiving the sample characteristic and comparing the sample characteristic to a fingerprint.
In yet another illustrative embodiment of the invention, a method of providing a light-emissive compound on a microplate is provided. The microplate has a substrate. The method includes the steps of selecting a substrate capable of absorbing at least one light-emissive compound thereon and depositing the at least one light-emissive compound on the substrate using a piezoelectric dispenser.
In still another illustrative embodiment of the invention a method of verifying authenticity of a sample product is provided. The method includes the steps of providing a microplate base having at least one light-emissive compound disposed thereon, applying a sample product to a microplate, irradiating the microplate with a predetermined wavelength of light, detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic, and comparing the sample characteristic to a fingerprint. The microplate has a solid base and a porous substrate layered on the base. The at least one light-emissive compound is absorbed in the substrate. Alternatively, at least one well integral with and opening into the top wall of the base may be provided. The at least one light-emissive compound is deposited into the at least one well. The at least one well has a semi-permeable membrane formed thereover. The semi-permeable membrane is adapted to allow the sample placed on the microplate to permeate from outside the at least one well into the at least one well while retaining the at least one light-emissive compound within the at least one well.
In another illustrative embodiment, a method of verifying authenticity of a sample product is provided. The method includes the steps of providing at least 500 micropores containing a dry light-emissive compound, absorbing a liquid sample into the micropores to permit the sample to solublize and interact with the light-emissive compound in the micropores, irradiating the micropores with a predetermined wavelength of light, detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic, and comparing the sample characteristic to a fingerprint.
Various embodiments of the present invention provide certain advantages and overcome certain drawbacks of the conventional techniques. Not all embodiments of the invention share the same advantages and those that do may not share them under all circumstances. This being said, the present invention provides numerous advantages including the noted advantage of providing light-emissive compounds on a substrate so that the compound and substrate may be used with product authentication equipment.
Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.